Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a first image of a first embodiment of a display screen orportion thereof with transitional graphical user interface showing ournew design;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof;

FIG. 5 is a first image of a second embodiment of a display screen orportion thereof with transitional graphical user interface showing ournew design;

FIG. 6 is a second image thereof;

FIG. 7 is a third image thereof;

FIG. 8 is a fourth image thereof;

FIG. 9 is a first image of a third embodiment of a display screen orportion thereof with transitional graphical user interface showing ournew design;

FIG. 10 is a second image thereof;

FIG. 11 is a third image thereof;

FIG. 12 is a fourth image thereof;

FIG. 13 is a first image of a fourth embodiment of a display screen orportion thereof with transitional graphical user interface showing ournew design;

FIG. 14 is a second image thereof;

FIG. 15 is a third image thereof; and,

FIG. 16 is a fourth image thereof.

The broken lines in the figures depict a display screen or portionthereof and form no part of the claimed design.

The appearance of the transitional graphical user interface sequentiallytransitions between the images shown in FIGS. 1-4, FIGS. 5-8, FIGS. 9-12and FIGS. 13-16. The process or period in which one image transitions toanother forms no part of the claimed design.

CLAIM We claim the ornamental design for a display screen or portionthereof with transitional graphical user interface, as shown anddescribed.